Engine shutdown valves are known and are specifically used to shut down engines so as to prevent over revving of the engine and the concomitant damage which can result and to terminate unsafe operations. Over revving of the engine can result when fuel or gas vapours which may be present in the atmosphere around the engine enter the air intake of the engine, thereby allowing combustion and continued operation of the engine even though the diesel fuel has been shut off.
One such engine shutdown valve is disclosed in our U.S. Pat. No. 4,537,386 entitled ENGINE SHUTDOWN VALVE. The valve there disclosed is specifically designed for the swing arm type application where minimal room is available along the air passage. The gate valve moves transverse to the direction of air flow in the '386 patent during its closing action.
A further shutdown valve is disclosed in our U.S. Pat. Nos. 4,215,845 and 4,285,494, both entitled ENGINE AIR CUT-OFF DEVICE. These patents both teach a shut down valve wherein the gate again moves transversely to the direction of air flow through the manifold and into the engine as in the '386 patent. The closure action, however, is not a pivoting actions as in the '386 patent. Rather, it is a linear motion which is useful in certain circumstances.